1. Field of Invention
This invention relates to an ink cartridge and an inkjet recording apparatus equipped with the ink cartridge.
2. Description of Related Art
An ink cartridge is typically loaded into an inkjet recording apparatus by mounting the ink cartridge into the inkjet recording apparatus. A rubber stopper is attached to the ink cartridge and prevents air, ink or any other material from entering or exiting the ink cartridge. The inkjet recording apparatus includes a hollow needle with an acuminate tip. When the ink cartridge is pushed and loaded into the inkjet recording apparatus, the hollow needle penetrates the stopper plug so that an inside of the ink cartridge is in communication with the hollow needle in order to supply ink to the inkjet recording apparatus. However, the acuminate tip of the hollow needle is formed with the acuminate tip projecting toward the user. It is thus necessary to employ safety measures in order to prevent a user from touching the tip.
In Japanese Unexamined Patent Application Publication H3-197052, for example, an inkjet recording apparatus is equipped with a protection device that protects the user from the hollow needle when the hollow needle is exposed. The protection device has a protection plate installed between the hollow needle and a side in which the ink cartridge is inserted in order to cover the hollow needle. When the ink cartridge is loaded, a lock of the protection plate when the protection plate is in a shielding position is released and the hollow needle is exposed. Furthermore, the hollow needle penetrates the stopper plug and the ink cartridge is thus loaded in the inkjet recording apparatus. Furthermore, when the ink cartridge is removed, the protection plate is placed in the shielding position by a twisted coil spring and held at that position by a lock component. Thus, the protection plate shields the user from touching the hollow needle.
As disclosed in Japanese Unexamined Patent Application No. 2001-113723, there also exist ink cartridges that prevent ink from leaking from the cartridges when the cartridges are removed from inkjet recording devices. Such ink cartridges are provided with an ink chamber that stores ink, an ink supply port that externally supplies ink stored in the ink chamber, and an ink guidance chamber formed between the ink chamber and the ink supply port.
The ink guidance chamber houses a valve unit, and a cylindrical packing is inserted into the ink supply port. The valve unit is urged by a compression spring in a direction elastically contacting the cylindrical packing in order to obstruct the ink flow path, and the valve unit prevents ink from leaking from the ink chamber side. The ink cartridge is structured such that, when attached to an inkjet recording device, an ink supply needle penetrates the cylindrical packing and opposes the urging force of the compression spring to press the valve unit toward the ink chamber. An ink flow path is thereby formed in order to supply ink.
There also exist ink cartridges, for example, in Japanese Laid-Open Patent Application No. 9-20018, in which the color of ink stored in the ink cartridge is easily recognized. Such ink cartridges include container bodies including porous materials into which ink is absorbed, and cover members that cover top openings of the containers. The cover members are formed of materials that are the same color as the ink absorbed by the porous materials. Therefore, even when ink cartridges of multiple colors are installed, because installation can be performed by recognizing the color of cover members of those ink cartridges, misinstallation of ink cartridges of different colors can be prevented. In addition, in order to recognize the color of the ink in the ink cartridge, ink cartridges formed from transparent or semi-transparent materials are also known.
There also exist ink cartridges, for example, in Japanese Laid-Open Patent Application 11-58775, to which a deaerating processing has been performed in order to store deaerated ink. The ink cartridge is included within a packaging body and the packaging body is held in a pressure-reduced state. The packaging body is held in a pressure-reduced state in order to suppress the deterioration of the deaerated ink while the ink cartridge is transported.
The inside of the ink cartridge is also divided into two spaces by a partition wall. Within the two spaces divided by the partition wall, one space is used as an ink supply chamber that temporarily stores ink that is supplied from an ink supply hole, and another space is used as an ink chamber that is filled by a porous member that can store ink. In order to store a large amount of ink, the ink chamber requires more space than the ink supply chamber. Because of this, the partition wall is arranged at a position that is significantly closer to an opposite end wall of the ink supply chamber.